As is illustrated in the cross-sectional view of an annular contact ball bearing shown in FIG. 3, known roller bearings 350 are typically comprised of an inner ring 360, an outer ring 370 and roller bodies 390. The roller bodies, e.g., balls, cones, cylinders, etc., are guided by a cage 380. In the following, ball bearings will be discussed as a representative example of the prior art.
FIG. 3 further shows the roller bearing 350 designed as an annular contact ball bearing, which is indicated by the diagonal axis 400. The cage 380 includes openings or pockets 410 for guiding the roller bodies and the roller bodies can be inserted into the openings or pockets 410. Thus, the roller bodies 390 are respectively guided in the pockets 410 during operation of the bearing 350. In addition, the cage 380 contributes to stabilizing the bearing and/or the bearing components during assembly of the bearing 350.
FIG. 4 shows a schematized cutout of the cage 380, which is formed in an annular manner and has been cut away at the cut lines 420 and 430. FIG. 4 further shows two pockets 410 that are formed to respectively receive two roller bodies, such as e.g., balls. A bridge 440 is located between the two pockets 410.
Snap-type cages are known that, after completely inserting all of the balls, are laterally pressed against the balls between the two bearing rings (oval clamping). In the alternative, snap-type cages may first receive all the balls, then may be mounted on a ring (inner- or outer ring) and subsequently may be finally assembled with a second ring (outer- or inner ring, if necessary, with the assistance of known physical aids such as warming up, cooling down, plastic deformation, etc.) into a self-retaining bearing.
Annular-guided, non-snap-type cages are another variant that initially receive all balls when placed over the inner ring. However, the balls must be held by an additional tool during the bearing assembly in order to subsequently be assembled with the outer ring into the bearing (if necessary, with the assistance of known physical aids such as warming up, cooling down, plastic deformation, etc.).
Snap-type cages are simple to assemble. However, only a limited number of roller bodies can be inserted, because the width of the bridge 440 of the cage between the pockets 410 must be designed bigger (longer) due to the snap-in forces, i.e. the bridge 440 must be relatively wide in order to be able to generate the necessary retaining force.
Non-snap-type cages can retain more roller bodies, because no forces act on such cages when the roller bodies are inserted. However, the roller bodies are not held by the cage, so that the final assembly of the bearing must be carried out in a substantially more costly manner, because the risk of the roller bodies falling out during the final ring mounting step exists.
Thus, both roller-body-guided (snap-type cages) and ring-guided cages have been utilized in the prior art. The latter have the advantage relative to the former that the bridge 440 between the roller bodies can be designed smaller and thus more balls can be retained in the same installation space. In this case, the bearing will have a higher load rating overall.
However, the disadvantage is that the roller bodies (e.g., balls) can not be retained by the cage during the assembly process, which makes the assembly process more complicated and/or burdensome.